The Avalon VT-747SP combines a creative STEREO tube-discrete Class A spectral-opto-compressor with a musical six band program equalizer, L-R output level and gain reduction metering and internal regulated power supplies in a 2U space. Ideal for high performance DAW input signal conditioning, stereo buss compression-EQ, stereo keyboards and analog mastering applications.

SPECTRAL-OPTO-COMPRESSION
The opto-compressor features a minimum signal path design utilizing sealed silver relays for all signal routing and by pass functions. The optical attenuator acts as a passive level controller with a Class A, variable gain make-up amplifier. Full dynamic control from soft compression to hard-knee limiting can be achieved with master threshold, ratio-compression, attack and release controls. Gain reduction indication is a large analog VU meter. Low frequency and high frequency contour parametric spectral controls can be routed into the side-chain path for enhanced frequency dependent compression with variable frequency and threshold levels. SC listen provides side-chain listen mode for monitoring.

SIX BAND PROGRAM EQUALIZER
The VT-747SP equalizer utilizes 100% discrete, Class A high-voltage transistors for optimum sonic performance. The six band STEREO program EQ incorporates the smooth characteristics of an all passive design. The frequency turnover, Q and amplitude ranges have been carefully chosen for each band to provide the most natural harmonic balance and lowest phase change while offering simple and effective tone control. The EQ can be placed pre or post the opto-compressor for enhanced effects.

TSP - TWIN SIGNAL PATH
The VT-747SP features TSP which gives you the choice of either tube tone or the classic, Class A discrete transistor sound by exchanging, three (3) high-voltage dual triode tubes with discrete amplifiers in the opto-compressor and primary output stages.

INPUT-OUTPUT and METERING
Fully balanced DC coupled, Class A discrete amplifiers are utilized for the input and output drive interface with+36dB input headroom. A high quality analog VU meter indicates accurate gain reduction. Twin 60dB range LED meters provide fast L-R output status of all levels.

VT-747SP FEATURES
* Stereo Class A opto-compressor with spectral control
* Stereo Class A six band discrete passive program EQ
* TSP twin signal path, vacuum tube bypass
* Low noise -92dB
* Fully balanced Class A input and DC coupled outputs
* Stereo dynamic 60dB high resolution output meters
* High quality analog VU meter for gain reduction
* High headroom+36dB input before overload
* Spectral side-chain monitor for pre listen
* EQ pre-post selection for opto-compressor
* Sealed silver relays for all signal routing
* Internal discrete regulated power supplies
* Military spec vacuum tubes for long life and low noise


VT-747SP SPECIFICATIONS
Circuit topology
Three (3) dual triode vacuum tubes (Sovtek 6922), high-voltage discrete Class A mode.
Input gain range
Balanced, Class A, 20k ohms, -20dB to +16dB with high gain switch
Maximum input level
+36dB balanced XLR pin 2 hot
Maximum output level
+30dB balanced 600 ohms, DC coupled, discrete Class A
Output type
XLR connector, output trim gain -45dB to +6dB
Noise 20kHz unweighted -92dB
Distortion THD, IMD 0.5%
Frequency response -3dB
1Hz to 200kHz
Gain reduction meter
High quality, illuminated gain reduction meter 0dB to -20dB range
Output meter
Twin 20 segment LED VU meters with -27dB to +30dB range
Compressor type
Optical passive attenuator
Make-up gain
Variable 0dB to +10dB stereo tracking
Threshold - Ratio
Threshold variable -30dB to +20dB, ratio-compression variable 1:1 to 20:1
Attack - Release
Attack variable 2mS to 200mS, release variable 100mS to 5 seconds
Side-chain spectral contour
Variable threshold -15dB to +15dB, frequency 70Hz to 9kHz twin ranges
Equalizer type Discrete Class A, passive design optimized for full range program material
Frequency bands (6)
Variable amplitude LF +/-24dB 15Hz shelf response
Variable amplitude MF1 +/-8dB 125Hz selected Q response
Variable amplitude MF2 +/-4dB 500Hz selected Q response
Variable amplitude MF3 +/-4dB 2kHz selected Q response
Variable amplitude MF4 +/-10dB 5kHz shelf response
Variable amplitude HF +/-20dB 32kHz shelf response
AC power
Internal toroidal 100v to 240v, 50-60Hz selectable, 70 watts maximum
Dimensions
19 x 12 x 3.5 in (482 x 305 x 89mm)
Weight 22lbs (10kg)
Dimensions-shipping carton
21 x 18 x 8 in (533 x 457 x 203mm)
Weight-packed
26lbs (11.8kg)